The city of Chattanooga, Tennessee will refund $8800 in red light cameras tickets issued to motorists trapped by an illegally short yellow time. Municipal Court Judge Russell Bean on Monday dismissed charges against 176 vehicle owners cited by an automated ticketing machine located at Martin Luther King Boulevard and Pine Street.

Last month, a motorist challenged his citation by insisting that the yellow light was too short and only remained lit for 3.0 seconds before changing to red and activating the camera. LaserCraft, the private vendor that runs the camera program in return for a cut of the profits, provided the judge with a computer database that asserted the yellow was 3.8 seconds at that location. Bean gave the motorist the benefit of the doubt and watched the video of the alleged violation while counting how long the light stayed yellow.

"It didn't seem to me that it was at four (seconds) because it would change right at three," Bean told the Chattanooga Times Free Press.

Bean then personally checked the intersection in question was timed at three seconds while other nearby locations had about four seconds of yellow warning. City traffic engineer John Van Winkle told Bean that "a mix up with the turn arrow" was responsible and that the bare minimum for the light should be 3.9 seconds. Judge Bean ordered 176 of the tickets issued within the first 0.9 seconds after the light turned red canceled.

Short yellow times are vital to ensuring the steady flow of traffic citations for vendors like LaserCraft. Confidential documents obtained in a 2001 court trial proved that the city of San Diego, California and its red light camera vendor, now ACS, only installed red light cameras at intersections with high volumes and "Amber (yellow) phase less than 4 seconds."

Short yellows trap drivers in what is known as a "dilemma zone" where there is neither time to stop safely -- without slamming the brakes and risking a rear-end collision -- nor to proceed through the intersection before it changes to red. Red light cameras capitalize on this, with four out of every five tickets issued before the light has been red for a full second, according to a report by the California State Auditor. This suggests that most citations are issued to those surprised by a quick-changing signal light.

In 2002, a Baltimore, Maryland judge caught the city trapping motorists at signals with illegally short yellow lights. (Read court memo)